Automatic vent controls



April 21, 1931. J. w. HARVEY AUTOMATIC VENT CONTROL Filed June 2, 1928 2 Sheets-Sheet l April 21, 1931- .17 w. HARVEY 1,802,252

AUTOMATI C VENT CONTROL Filed June 2. 1928 2 Sheets-Sheet 2 Patented Apr. 21, 1931 UNITED STATES PATENT OFFICE JESSE W. HARVEY, OF COLLINS, GEORGIA, ASSIGNOR TO MOORE DRY KEN COMPANY,

' OF JACKSONVILLE, FLORIDA, A CORPORATION OF FLORIDA AUTOMATIC VENT CONTROLS Application filed June 2, 1928.

This invention relates to an improvement in automatic vent controls.

The object of the invention is to automatically control the venting of a dry kiln and simultaneously automatically control the supply of air admitted to the kiln.

As is well understood in dry kiln 0peration, there is a controlled valve in the main feed line supplying steam to the heating coils, which is thermostatically controlled,

, and also a similar valve in the steam spray line, both of thesecontrolled valves being controlled by an automatic humidity and temperature controller, thereby maintainlng automatic control over both the temperature and humidity within the dry kiln.

The present invention adds additional valves to this system for automatically controlling the inlet of fresh air into the kiln,

as well as the ventilators in the roof of the kiln which regulate the discharge of excess moisture. In this way, perfect control is obtained over the humidity inside of the kiln, preventing it from going too high or too low, which is accomplished by regulat ing the ventilating opening and the fresh air intake opening when the wet bulb reading on the humidity control runs above the set point. When fresh air intakes are controlled by hand, there is almost invariably an admission of more fresh air than necessary or either too little, causing a loss in the control over the humidity, degrading the lumber.

The automatic ventilator control which likewise-regulates the fresh air intake gives perfect control over the hum1d1ty,gre gardless of the inside temperature or moisture content of the lumber.

In the accompanying drawmgs: w Fig. 1 is a diagrammatic view of the invention as applied to a dry kiln;

Fig. 2 is a side elevation of the controlled diaphragm valve; v Figs. 3 and 4 are side elevations of modifications in the damper and shutter operators; and

Fig. 5 is a diagrammatic side elevation of an electrical system for controlling the o valves.

Serial No. 282,373.

One end of the kiln is illustrated and is designated generally by the numeral 1, be ing provided with the ventilators 2 in the roof thereof, as well known and customary in the art.

An automatic humidity and temperature control instrument is designatedby the numeral 3 and since this is well known in the art as well as its operation and construction, it is not described in detail. One form of instrument which may be used is shown in the patent to Foote,No. 1,593,625, of July 27, 1926. Wet and dry bulb thermometers 3a and 3b are located in the drying chamber and connected with the instrument 3, as shown in said patent, as a means of control, according to atmospheric conditions in the kiln. An air supply pipe 4 is connected with the instrument as well as air pipes 5 and 6, which lead from the instru ment. The air pipe 5 extends toan air operated valve a which controls the steam supply to the heating system a2 in the kiln, while the air pipe 6 extends to a similar air operated valve 61 controlling the steam spray system 62 in the kiln.

These are well known and their operation understood by those familiar with the art as automatically controlling the temperature and humidity Within a kiln.

A branch line 7 connects the line 6 with a controlled valve 8, which is caused to open by the instrument, allowing electric power, air from the main air, liquid or steam supply pipe 9 to enter the line 10 and pass'into the cylinder 11 or electric motor. This cylinder or motor is mounted upon a suitable framework 12 preferably upon the roof of the kiln, as shown in the drawings. A'piston operates in the cylinder 11 and is connected with a rod 13, which, in turn, is connected to arms 14 of dampers 15, one of which is located in each of the ventilators2. A counterweight 16 may be connected by a cable 17 to the rod 13 or for otherwise returning the dampers to their open positions whenever the air pressure is released from the cylinder 11. A 'branch'line 18 extends from the line 10 to cylinder 19 within which is also mounted a piston operating a rod 20. This rod 20 is connected with arms 21 pivoted as at 22 and having shutters 23 carried thereby. These shutters are ,in position to be moved over the ends of or within fresh air supply pipes 24 to close these pipes and regulate the admission of fresh air into the kiln therethrough. A counter weight 25 also serves to return the shutters to their open positions, whenever the air is released from the air cylinder 19.

The controlled valve 8 is of well known construction but it has a lever 25 suitably connected with and operated by its own movement, which lever 25 is operatively connected with levers 26 and 27. The lever 27 is connected with the handle 28 of vent valve 29 for opening the vent valve when the valve 8 1s closed in order to release the pressure in the cylinders 11 and 19.

In the operation of the automatic control system air is admitted to the control .lnstrument 3 through the tube 4, leaving the mstrument through the lines and 6, to the automatic air controlled valves, WhlCl'l regulates the admission of steam to the sprays and heating system within the kiln. The valve 8 also receives air from the pipe 6, causing it to open, allowmg air pressure from the main air, steam or liquid supply pipe 9 to enter the pipes and 18 andthe cylinders 11 and 19, closing the dampers in the ventilators and the shutters 23 over or within the fresh air inlets 24. This allows the kiln to reach its set point of humidity and temperature equally.

After the set point is reached, the main controlled valves are closed as the air pres sure is cut off automatically by the control instrument, which also cuts off the pressure in the cylinders 11 and 19, allowing the air, steam or liquid from the cyllnders to escape through the vent valve 29 opened by the closing of the diaphragm valve 8 and causing the opening of the dampers 15 and, shutters 23 by the counter weights 16 and 25, clearing the kiln of excess moisture equally but by reason of the operation of the heating control valve the steam in the heating coils is maintained, keeping the heat up to 1ts set point. a

This automatic control of the vents as well as the fresh air intake in the kiln maintains the proper humidity within the kiln and up to its set point at all times. In order to do this it is essential that fresh air be admitted automatically accordinglyas the vents are .opened, letting out the moistened air in the kiln.

The automatic regulation of not only the vents of the kiln but also the air admission to the bottom of the kiln very greatly adds to its successful operation, increasing the quality of the drying operation because of the obs'olute control over the humidity in the kiln. A great saving is also obtained in cylinder: 11 communicates with the pipe 10.

and has a piston therein, with which is connected a piston rod 30 extending through a bracket 31, and pivotally connected at its outer end to an arm 32, which, in turn, is con nected with and actuates the damper 15. A spring 33 is sleeved over the piston rod 30 and interposed between the bracket 31 and an abutment 34, adjustably secured on the piston rod 30, for exerting a tension on the piston rod to return the piston to its initial posit-ion upon release of the air pressure from the cylinder 11, and, the damper 15.

7 As shown in the modification, illustrated in Fig. 4, the vent control cylinder 19 has the piston rod 2,0 thereof connected with an arm .35 connected with a shutter 36 mounted in the fresh air duct 24. A spring 37 is sleeved on the piston rod 20 and interposed between a bracket 38 and an abutment 39 adjustably secured on the rod 20 for returning the shutter to its open position'upon release of the air pressure from the cylinder 19.

If it should be desirable, the control may be of'either the top or bottom air vents alone 'without the others. Likewise, any number of rows or of individual ventilators and fresh air vents may be used, according to the drying conditions.

In place of the air operated controller 3, an electrically operated controller may be used if this should be desired,'to regulate the valve of the steam heating and spray lines and the valve 8. i

This is illustrated in the modification shown in Fig. 5, in which the electrical controller is designated generally by the numeral 40 regulating the supply of current thpough the line 41 to the electric motor operatc d valve 42 for regulating the supply of air, steam' or fluid as before described. In other words, the valves. may be regulated electrically instead of by fluid. pressure, if this should be desired.

I claim 1. In a drying chamber having fresh air inlet and vent, the combination of means for controlling the air inlet and vent, heating systems for the chamber, a steam spray system for the chamber, a source of fluid supply,

power actuated means responsive to drying conditions'within the chamber for regulating the communication of the source of fluid supply with the air inlet and vent controlling means fon regulating said last-mentioned means, and means other than said power actuated means and responsive. to drying, conditions in the chamber forcontrolling the heating and spray systems for the chamber.

2. In a drying chamber having fresh air inlet and vent, the combination of means for likewise to open valve and responsive to drying conditions in the chamber for controlling the heating and spray systems for the chamber.

3. In a drying chamber, having fresh air inlet and vent, the combination of fluid controlled dampers for controlling the air inlet and vent, heating and air moistening systems for the chamber, a source of fluid supply adapted to communicate with the fluid controlled dampers for the air inlet and vent, a

valve for controlling said communication and causing a simultaneous actuation of the air inlet and vent dampers, power actuated means responsive to drying conditions within the chamber for regulating the controlling valve, and means other than said power actuated means and valve and responsive to drying conditions within the chamber for controlling the heating and air moistening systems independently of the airinlet and vent.

4. In a drying chamber, the combination of means for controlling air circulation for said chamber, a source of power supply for operating said controlling means, means for connecting the source of power supply with the controlling means, a second source of power supply, and a controller responsive to drying conditions within the chamber for connecting the second source of power supply with the connecting means for causing an actuation of said means.

5. In a drying chamber, the combination of means for controlling air circulation for said chamber, a source of fluid supply for operating said controlling means, power operated means for connecting the source of fluid supply with the controlling means, a source of power supply, and a controller responsive to drying conditions within the chamber for connecting the last-mentioned source of powor supply with the power operated means for causing an actuation of said means.

6. In a drying chamber, the combination of fluid actuated means for controlling air circulation for said chamber a source of fluid supply for said controlling means, power operated means for connecting the source of fluid supply with the controlling means, heat I and humidity controlling means for the chamher, a source of power supply for said heat 7. In a drying chamber, the combination of fluid actuated means for controlling air circulation for said chamber, a source of fluid supply for said controlling means, a power operated valve for connecting-the source of fluid supply with the controlling means, separate heat and humidity controllingmeans for the chamber, a second source of fluid supply, and a controller responsive to drying conditions within the chamber for connecting the second source of fluid supply with the heat and humidity controlling means and the power operated valve.

In testimony whereof I afiix my signature.

JESSE W. HARVEY.

and humidity controlling means, and a controller responsive to drying conditions with in the chamber for connecting the last-mentioned source of power supply with the heat and humidity controlling means and with the power operated means. 

